US3511426A

US3511426A - Mechanism for intermittently advancing and stopping material

Info

Publication number: US3511426A
Application number: US750898A
Authority: US
Inventors: La Grange D Whitmore; Roy E Sherman
Original assignee: Control Data Corp
Current assignee: Control Data Corp
Priority date: 1968-08-07
Filing date: 1968-08-07
Publication date: 1970-05-12
Anticipated expiration: 1987-05-12

Description

May 12,1970 LA GRANG ED. WHITMORE EI'AL 3,511,426 MECHANISM FOR INTERMITTENTLY ADVANCING AND STOPPING MATERIAL Filed Aug. '7, 1968 4 Sheets-Sheet 1 if 70/4/12 K5 y 1970' LA GRANGE o. WHITMORE E A 3,511,426

MECHANISM FOR INTERMITTENTLY ADVANCING AND STOPPING'MATERIAL Filed Aug. '7, 1968 I 4 Sheets-Sheet 2 Z a 6. 419 G-ZZDM/f/Vi F0 :15 SflfF/WHA/ y 1970 LA GRANGE D.'WHITMORE 'ETAL 3,511,426

r MECHANISM FOR .INTERMITTENTLY ADVANCING AND STOPPING-MATERIAL v Filed Aug. '7, 1968 v j 4 Sheets-Sheet 3 I F? HE By l :40;

y-1 0 LA GRANGE D. WHITMORE ETI'AL 3,511,426

. MECHANISM FOR INTERMITTENTLY ADVANCING AND STOPPING MATERIAL Filed Aug. V, 1968 4 Sheets-Sheet 4.

| l 04w Poi/El pen 5 Ill/7'5 570/ M6775 I s/mFr vfmc/rr United States Patent O U.S. Cl. 226145 7 Claims ABSTRACT OF THE DISCLOSURE An improved mechanism is provided for advancing continuous length paper, and other lengths of materials, in accordance with a precise stepwise advancement. The mechanism includes a pair of wheels between which the material is advanced, and one wheel functions as a drive wheel for intermittently advancing the material. The drive wheel is rotated by a drive shaft which is oscillated back and forth about its axis of rotation, and a stopping mechanism precisely stops the drive shaft in a position which advances paper between the pair of Wheels. The drive shaft may be driven by an electromagnetic solenoid coil which periodically draws a rotor member carried by the drive shaft into an air space formed within the coil. When the rotor is drawn into the coil, the drive shaft functions to turn the drive wheel in a direction which advances paper, and a return spring turns the drive shaft in an opposite direction when the solenoid coil is de-energized. The stopping mechanism for precisely stopping forward advancement of material may comprise a ratchet means carried by the drive wheel. A cam plate is mounted adjacent to the ratchet means, and a pawl is lifted ard lowered by the cam plate relative to the ratchet means to periodically engage a tooth of the ratchet for precisely stopping the forward rotation of the drive shaft.

BACKGROUND AND BRIEF DESCRIPTION OF INVENTION This invention relates to mechanisms for advancing paper and other material, and in particular, the invention is concerned with an improved mechanism for advancing continuous length paper and for intermittently stopping the advancement for a precise period of time so that a collateral operation, such as printing, can be carried out. The improved mechanism of the present invention permits very high speed advancements of a material.

It is known in the prior art to provide for various mechanisms and means for advancing paper and other materials. Also, it is known to advance paper on an intermittent program whereby the paper is periodically stopped before a subsequent advancement. Representative of the prior art on this subject are the mechanism shown in the U.S. Pats. 948,944; 1,827,652; 2,077,925; 2,311,903; 2,530,961; 2,541,013; 2,912,100; 3,125,309; and 3,292,832. As can be appreciated from the disclosures of the just mentioned patents, many of the prior art devices on this subject have consisted of relatively complex apparatus requiring a large number of precisely manufactured and carefully related elements. In contrast the present invention offers a relatively simple mechanism for intermittently advancing and stopping the movement of a material in a single direction and with such precision that a printing operation, or other collateral functions, can be performed on the same material. Although the invention will be deinvention be applied in any situation where it is desired to intermittently advance and stop a material. The material may be in the form of a sheet, card, film, or other data receiving or recording form, and collateral functions such as printing, punching, or recording, may be carried out in connection with the intermittent advancement of the material.

In its basic form, the mechanism of this invention includes a pair of wheels, or equivalent devices, which function to receive and advance a material between them. One wheel functions as a friction wheel for preventing backward movements of the material, and the second wheel functions as a drive Wheel for applying periodic forward movements to the material. Thus, periodic advancements of the material between the two wheels is accomplished in a single forward direction. The drive wheel is periodically advanced about its axis of rotation by a drive shaft means connected to the wheel. A one-Way clutch between the drive wheel and the drive shaft means is such that the drive wheel is engaged by the drive shaft only during rotations of the drive shaft which will advance material in the desired direction between the drive wheel and the friction wheel. Opposite rotations of the drive shaft are not imparted to the drive wheel, thereby preventing a backing up of the material. A driving means is operatively associated with the drive shaft to oscillate the drive shaft back and forth about its axis of rotation. In one form of the invention the driving means may include a solenoid which is periodically energized with electric current to draw a rotor into the solenoid. The rotor is rigidly fixed to the drive shaft such that the drive wheel is rotated for an advancing movement of paper when the rotor is drawn into the solenoid. When the solenoid is de-energized, a return spring draws the rotor and the drive shaft back to a starting position for a subsequent rotation in a forward direction.

A stopping mechanism is associated with the drive wheel means for positively and precisely stopping the advancement of material by the drive wheel. Although the material can be stopped by merely de-energizing the solenoid, it is important to be able to advance material for a precise distance and to stop the material for a precise period of time so that collateral operations, such as printing, can be carried out on the same material. Thus, the stopping means functions to precisely stop an advancing movement of the material near the end of its intermittent advancement. The stopping means may comprise a ratchet which is fixed to the drive wheel, and an associated cam plate may be carried by the drive shaft for dictating movements of a pawl relative to the ratchet. The pawl may be associated with the ratchet so as to be normally biased into engagement with teeth formed in the ratchet, and the cam means is of a configuration to periodically lift the pawl out of engagement with the ratchet. In one form of the invention, the cam plate is fixed to release the pawl near the end of a rotation of the drive shaft in the direction which advances material. Also, the cam means is of a configuration to periodically lift the pawl out of engagement with the ratchet during opposite motions of the drive shaft. The drive wheel and friction wheel may be mounted on separate shafts which are parallel to each other, and each wheel may be provided with one-way clutching devices which permit rotational movements only in directions which accommodate the advancement of a material between the two wheels.

With the mechanism of the present invention, there is provided a relatively simple apparatus which is easily manufactured and maintained, and the apparatus is very precise in dictating advancing and stopping movements to paper, film, or any other material which must be intermittently advanced. Additional details and advantages of the present invention will become apparent in the more detailed discussion which follows. In the detailed discussion reference will be made to accompanying drawings as further identified below.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of one embodiment of the basic mechanism of the present invention as seen at the beginning of an oscillation which will advance material between the drive wheel and a friction wheel;

FIG. 2 is a perspective view similar to that of FIG. 1 but showing relationships of elements in the mechanism when an advancing motion has been carried out and stopped;

FIG. 3 is an end elevational view of a slightly different arrangement of the basic mechanism shown in FIG. 1;

FIG. 4 is a side elevational view of the mechanism shown in FIG. 3;

FIG. 5 is a top plan view of the FIG. 3 mechanism, with certain portions omitted from the drawing for clarity; and

FIG. 6 is a graphic example of a typical operation of the mechanism when used in connection with a printing operation.

DETAILED DESCRIPTION OF THE INVENTION As discussed above, the present invention provides for an improved mechanism which may be used for precisely advancing and stopping paper, or other material, for increments of advancement in a single direction.

Referring to FIGS. 1 and 2, basic elements of the mechanism of the present invention are illustrated. The illustrated mechanism includes a pair of wheel means which includes a drive wheel means 10 and a friction wheel means 12. The pair of wheels are positioned relative to one another to frictionally contact opposite surfaces of a flat form of material 14 which is to be intermittently advanced between the pair of wheels. The material 14 may be in the form of a paper strip, card, film, ribbon, drive belts, or in any other form for being periodically advanced in conjunction with a pair of wheels 10 and 12. The pair of wheels may be mounted on shafts, which are substantially parallel to one another, as illustrated, and a shaft 16 which is associated with the drive wheel means 10 may be considered a drive shaft means. The drive wheel means 10 functions to frictionally engage one surface of the material 14 so as to advance the material in the direction of the arrow when the drive wheel means 10 is rotated in an advancing direction (clockwise as viewed in FIGS. 1 and 2) about the central longitudinal axis of the drive shaft means 16. The friction wheel means 12 functions to support the material 14 on an opposite surface while it is being advanced and to prevent a backward movement of the material after it has been advanced for a predetermined distance. Each of the wheels 10 and 12 may be mounted on their respective shafts with one-way clutch bearings of known construction (see for example the type of clutching mechanism illustrated in US. Pat. 1,513,021). The friction wheel means 12 is provided with one-way clutch bearings which permit free rotational movements only in a counterclockwise direction, as viewed in FIGS. 1 and 2, and the drive wheel means is provided with a one-way clutch bearing means which permits driving movements of the wheel 10 only in a clockwise direction of movement, as illustrated. Thus, the pair of wheels 10 and 12 are provided with clutching mechanisms, or their equivalents, which permit rotational movements of the two wheels only in directions which accommodate the desired advancement of the material 14 in a single direction between the pair of wheels.

The drive wheel means 10 is rotated for a limited distance about its axis of rotation by a driving means which is operatively associated with the drive shaft means 16.

As explained above, the drive wheel means 10 is mounted on the drive shaft 16 so as to be driven only in a direction which accommodates advancement of material. To accomplish intermittent advancing rotations of the drive wheel means 10, the drive shaft means 16 is oscillated back and forth about its axis of rotation (the central longitudinal axis of the drive shaft). Rotation result in an engagement of the drive shaft means (through the one-way clutch mechanism) with the drive wheel means 10 so as to rotate the drive wheel means 10. Such rotations result in an advancing of the material 14 between the wheels 10 and 12 because of the frictional engagement of the drive wheel means 10 with an upper surface of the material 14. However, rotations of the drive shaft means 16 in an opposite direction (i.e., a counterclockwise direction as viewed in FIGS. 1 and 2) result in no substantial turning movement of the wheel means 10 in a counterclockwise direction because the one-way clutch mounting of the drive wheel 10 permits free movement of the drive shaft relative to the drive wheel when the drive shaft is rotated in a counter-clockwise direction. Thus, the drive shaft means 16 is rocked back and forth about its axis of rotation for periodically rotating the drive wheel means 10 in a direction which advances paper between the drive wheel and the frictional wheel means 12. A preferred form of driving means for oscillating the drive shaft 16 back and forth is illustrated by solenoid coil means 18 and rotor means 20 of FIGS. 1 and 2. The solenoid coil may be of any well known construction, and it includes circuiting means for automatically energizing and de-energizing the coil by a flow of electrical current through the coil. Since the solenoid itself is not a separate part of the present invention, a circuiting diagram and associated electrical components have been omitted from the drawings. When the solenoid coil 18 is energized by a flow of current, a magnetic field is established in an air gap formed in the solenoid core. During such energization of the coil, the rotor 20 is drawn downwardly into the air gap from the position shown in FIG. 1 to the position shown in FIG. 2. The rotor means 20 is fixed in its mounted relationship to the drive shaft means 16, and therefore, downward movements of the rotor result in a clockwise rotation of the drive shaft 16. As described above, a clockwise rotation of the drive shaft applies a similar clockwise rotation to the drive wheel means 10 for effecting an advancement of paper between the drive wheel 10 and a friction wheel 12. Thus, there is provided in the coil 18 and rotor 20 combination a driving means for periodically rotating the drive shaft 16 in a direction which causes an advancement of paper by the drive wheel means 10. When the coil 18 is de-energized, the rotor 20 is returned to its FIG. 1 position by a return spring means 22 which is biased to normally rotate the drive shaft means 1'6 and rotor 20 in a counterclockwise direction to the position shown in FIG. 1.

It can be appreciated that the elements described so far provide for a periodic, stepwise advancement of paper, or other material in a single direction. However, such an advancement is difficult to control at very high speeds, and precise control becomes important when collateral operations, such as printing, cutting or punching are to be carried out at precise locations on the material or at precise times as related to movement of the material. Accordingly, a stopping mechanism is incorporated in the apparatus of the present invention to provide for a precise, periodic stopping of the material 14 near the end of each advancement movement.

The stopping mechanism which is associated with the apparatus of this invention comprises means for rapidly and precisely stopping and braking advancing (clockwise in FIGS. 1 and 2) movements of the drive Wheel means 10 near the end of each advancing rotation of the drive shaft means 16. Although the stopping means may be provided in several forms, one embodiment of a very practical stopping mechanism is illustrated in FIGS.

1 and 2. The stopping mechanism which is illustrated includes a ratchet means 24 and a cam plate means 26. The cam plate means 26 is fixed to the drive shaft means 16, and thus, the cam plate means 26 oscillates back and forth with all rotational movements of the drive shaft means about its central longitudinal axis. The ratchet means is fixed to the drive wheel so that direct control of the drive wheel may be accomplished, and the ratchet means is mounted relative to the drive shaft 16 to be free of non-advancing rotation of the drive shaft means. A single pawl element 28 is provided for cooperation with the ratchet means 24 and the cam plate means 26 to control advancing and stopping movements of the drive wheel means 10. The pawl 28 is positioned to have a normal bias in the direction of the ratchet means 24, and the cam plate means 26 functions to lift the pawl 28 out of engagement with the ratchet means 24. As seen in FIG. 1, the cam plate means 26 is of such a configuration that the pawl member 28 is normally lifted out of engagement with the ratchet means 24 during initial advancing movements of the drive shaft means 16 and during all return rotations of the drive shaft means from the position shown in FIG. 2 to the position shown in FIG. 1. However, when the solenoid coil 18 is actuated to draw the rotor 20 downwardly, to the position shown in FIG. 2, a cam surface 30 on the cam plate means 26 allows the pawl member 28 to fall into engagement with a ratchet tooth 32 of the ratchet means 24.

Considering a typical operation of the mechanism illustrated in FIGS. 1 and 2, an energization of the coil 18 will result in a downward movement of the rotor 20. Such. movement results in a rotational oscillation of the drive shaft means 16 in a direction which drives the drive wheel means (and its associated ratchet means 24) clockwise for advancing the material 14 between the drive wheel means 10 and the friction wheel means 12. As the rotor 20 moves downwardly to the position shown in FIG. 2, the cam plate means 26 is carried through an arc of rotation which corresponds to the clockwise rotation of the drive shaft means 16. Near the end of the rotation of the drive shaft means 16, the coil 18 is de-energized and the pawl 28 falls downwardly into engagement with a tooth 32 of the turning ratchet means 24. This engagement causes a rapid stopping of the ratchet means 24 and of the drive wheel means 10. In this manner, the distance of rotational movement of the drive wheel 10 and its associated drive shaft 16 is precisely controlled and limited by the configuration of the cam surface 30 and the time at which the pawl 28 engages the ratchet tooth 32. Thus, the distance of advancement of material 14 is carefully controlled and limited. A sprague spring 34 may be provided for contacting a surface of the drive wheel means 10 to prevent a backlash of the drive wheel means 10 immediately after impact of the pawl 28 with the ratchet tooth 32. Also, the friction wheel means 12 assists in preventing any momentary backup of the paper 14 since a one-way clutch prevents the frictional wheel means 12 from rotating in a clockwise direction. The shaft upon which the friction wheel 12 is mounted is a fixed shaft and does not rotate in the embodiment illustrated in FIGS. 1 and 2. When the advancing paper has been stopped by the mechanism, and is in the position shown in FIG 2, de-energization of the solenoid coil 18 permits a reverse rotation of the drive shaft means 16 in a counterclockwise rotation. The reverse rotation of the drive shaft means 16 permits a resetting of the mechanism for a subsequent advancing movement. As shown in FIG. 1, a stop limit means 36 may be provided to limit the return motion of the drive shaft means 16 under the influence of torsion spring 22. The limit means 36 may include an adjustable screw which is threaded within a fixed cane be carefully set and adjusted.

It should be understood that the mechanism illustrated in FIGS. 1 and 2 is intended to disclose the basic elements and relationships of the present invention. Of course, all elements are assembled and mounted in a suitable housing, or in connection with other structures which fix the relationships defined above. FIGS. 4 through 5 illustrate the m chanism of the present invention in a form in which it may be utilized in an actual operation for intermittently advancing material. The relationships of the various elements have been re-arranged somewhat from what is shown in the perspective views of FIGS. 1 and 2, but it can be appreciated that the drive wheel means 10 and its associated driving and stopping means may be arranged in any suitable attitude in ccordance with the principles of the present invention. FIG. 5 is incomplete to the extent that the ratchet means 24, the cam plate means 26, and the pair of wheels 10 and 12 have been omitted from the drawings so that the pawl 28 and the spring 34 are fully illustrated.

FIG. 6 illustrates a typical working cycle for the mechanism of the present invention when utilized in combination with printing apparatus. It is contemplated that the invention may be used in a variety of situations where it is desired to precisely advance and stop a running length of material, and one such situation involves a use of the mechanism in combination with a printing device. With the improved characteristics of the device of this invention, it is possible to advance paper in a stepwise manner for receiving printed information from a printing mechanism. As an example of operation, it is possible to print at the high rate of 1800 or 2400 lines per minute with 12 or 15 characters respectively being applied to each line during the stopped intervals of the periodically advancing paper. Where such high speed printing is involved, it is necessary that the increments of movement of the paper be precise in distance and in timing relative to the printing operation which is taking place concurrently with the advancement of the paper. FIG. 6 is a timing diagram of a system which advances paper for printing at the rate of approximately 40 lines per second, and all times referred to on the graph are in milli-seconds. It can be seen that the coil 18 is de-energized just prior to the time that the pawl 28 engages and stops the ratchet 24 during each cycle. Other examples of operation include the application of information and color codes to tickets, and punching or cutting operations may be combined with such printing treatments of the advancing paper.

Having described the structural features of the mechanism of this invention, it can be seen that a relatively simple mechanism has been provided for effecting a very rapid, but carefully controlled, intermittent advancement of a length of material. The mechanism may be manufactured from known materials which provide the desired functions and wearing characteristics, and equivalent structures may be substituted for the illustrated embodiments of the invention. The pair of Wheels 10' and 12 are provided with surfaces which make a frictional contact with whatever material is being advanced, and equivalent structures may be substituted for the drive and friction wheels which have been illustrated. All equivalent and obvious variations of the disclosed mechanism are intended to be included within the scope of this invention as claimed below.

What is claimed is:

1. A mechanism for automatically and intermittently advancing lengths of material for predetermined distances in a single direction of movement, comprising:

a drive wheel means and a friction wheel means positioned relative to one another to receive between them the material which is to be advanced, said friction wheel means being mounted on a shaft so as to rotate only in a direction which will accommodate said single direction of movement for said material,

a drive shaft means connected to said drive wheel means for rotating said drive wheel means only in a direction which advances said material in said single direction when the material is positioned between the drive wheel means and the friction wheel means,

driving means operatively associated with said drive shaft means to oscillate the drive shaft means back and forth about its axis of rotation,

a ratchet means fixed to said drive wheel means for movement therewith,

a pawl means positioned and biased to contact said ratchet means to periodically stop rotational movement of said drive wheel means in the direction which drives said drive Wheel means and which advances the material,

a cam means fixed to said drive shaft means for lifting said pawl means out of engagement with the ratchet means, said cam means being of a configuration (a) to periodically release said pawl means for a stopping engagement with said ratchet means during a rotation of the drive shaft in one direction of rotation, and (b) to periodically lift said pawl means out of engagement with said ratchet means during a rotation of the drive shaft means in an opposite direction of rotation, whereby said material is advanced between the drive wheel means and the friction wheel means during oscillations of said drive shaft means in said one direction of movement and wherein said advancement is stopped at a predetermined point when said pawl means engages and stops the ratchet means.

2. The mechanism of claim 1 wherein driving means includes an electromagnetic means comprising a rotor and a solenoid coil combination of the type in which the solenoid coil can be periodically magnetized to draw the rotor into an air space formed in said solenoid coil, said rotor member being fixed to said drive shaft means.

3. The mechanism of claim 2 wherein said drive shaft means is turned in said one direction of rotation by an energization of said solenoid coil, and including a return spring means for rotating said drive shaft means in an opposite direction of movement whenever said solenoid coil is de-energized.

4. The mechanism of claim 1 wherein said drive wheel means is connected to said drive shaft means with a oneway clutch means which permits driving movements to be applied to said drive wheel means only when said drive shaft means is rotated in said one direction of rotation.

5. The mechanism of claim 1 wherein said friction wheel means is mounted on a fixed shaft having a longitudinal axis substantially parallel to the longitudinal axis of the drive shaft means, and including a one-way clutch means for connecting said friction wheel to said fixed shaft so that said friction wheel can rotate only in a direction which accommodates the advancement of material between the drive wheel means and the friction wheel means 6. The mechanism of claim 1, and including a braking member which contacts said drive wheel means to prevent backlashing of the drive wheel means when it is stopped.

7. A mechanism for automatically and intermittently advancing lengths of material for predetermined distances in a single direction of movement, comprising:

a drive wheel means and a friction wheel means positioned relative to one another to receive between them the material which is to be advanced, said friction wheel means being mounted on a shaft so as to rotate only in a direction which will accommondate said single direction of movement for said material,

driving means operatively associated with said drive shaft means to rotate the drive shaft means back and forth about its axis of rotation,

stopping means for stopping oscillations of said drive Wheel means in said single direction which advances material between the drive wheel means and the friction wheel means, said stopping means including a cam means for actuating said stopping means, whereby material is automatically advanced and stopped for a period of time before a subsequent advancing movement is begun.

References Cited UNITED STATES PATENTS 3/1957 Forkner 226145 X 3/1959 Panissidi 226156 RICHARD A. SCHACHER, Primary Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 5 11 4 26 Dated 1 2 1970 lnventofls) LaGrange D. Whitmore and Roy E. Sherman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

At the heading of each drawing and immediately following the title in column 1 the principal inventor's first name is incorrectly broken up into two words. In each instance the name "La Grange" should read LaGrange Column 1, line 56, "mechanism" should read mechanisms Column 4, line 7, "Rotation" should read Rotations of the drive shaft means 16 in a clockwise direction Attest:

Ed Emma h mm x. sauuw. Ja- Auestmg 0mm comissioner or Pam" FORM PO-IO5O (IO-69] USCOMM DC 60376-959 w u s covenant!" nmnmc ornc: nus 0-166-334